From 3e4c3863e0cfb8c2abdff6bb494ca69d3d2aed9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
Date: Sat, 10 Jun 2023 17:01:40 +0200
Subject: [PATCH] mips: bmips: dma: fix CBR address
MIME-Version: 1.0
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Some BCM63xx SoCs may return CBR address as 0.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 arch/mips/bmips/dma.c   | 12 ++++--------
 arch/mips/bmips/setup.c | 11 ++++-------
 2 files changed, 8 insertions(+), 15 deletions(-)

--- a/arch/mips/bmips/dma.c
+++ b/arch/mips/bmips/dma.c
@@ -5,11 +5,10 @@
 #include <asm/bmips.h>
 #include <asm/io.h>
 
-bool bmips_rac_flush_disable;
+void __iomem *bmips_cbr_addr;
 
 void arch_sync_dma_for_cpu_all(void)
 {
-	void __iomem *cbr = BMIPS_GET_CBR();
 	u32 cfg;
 
 	if (boot_cpu_type() != CPU_BMIPS3300 &&
@@ -17,11 +16,8 @@ void arch_sync_dma_for_cpu_all(void)
 	    boot_cpu_type() != CPU_BMIPS4380)
 		return;
 
-	if (unlikely(bmips_rac_flush_disable))
-		return;
-
 	/* Flush stale data out of the readahead cache */
-	cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
-	__raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG);
-	__raw_readl(cbr + BMIPS_RAC_CONFIG);
+	cfg = __raw_readl(bmips_cbr_addr + BMIPS_RAC_CONFIG);
+	__raw_writel(cfg | 0x100, bmips_cbr_addr + BMIPS_RAC_CONFIG);
+	__raw_readl(bmips_cbr_addr + BMIPS_RAC_CONFIG);
 }
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -90,7 +90,7 @@
 
 #define DDR_CSEND_REG		0x8
 
-extern bool bmips_rac_flush_disable;
+extern void __iomem *bmips_cbr_addr;
 
 static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
 
@@ -171,12 +171,6 @@ static void bcm6358_quirks(void)
 	 * disable SMP for now
 	 */
 	bmips_smp_enabled = 0;
-
-	/*
-	 * RAC flush causes kernel panics on BCM6358 when booting from TP1
-	 * because the bootloader is not initializing it properly.
-	 */
-	bmips_rac_flush_disable = !!(read_c0_brcm_cmt_local() & (1 << 31));
 }
 
 static void bcm6368_quirks(void)
@@ -209,6 +203,11 @@ static void __init bmips_init_cfe(void)
 
 void __init prom_init(void)
 {
+	if (!(read_c0_brcm_cbr() >> 18))
+		bmips_cbr_addr = (void __iomem *) 0xff400000;
+	else
+		bmips_cbr_addr = BMIPS_GET_CBR();
+
 	bmips_init_cfe();
 	bmips_cpu_setup();
 	register_bmips_smp_ops();
